Table 3.

Variables and assignments

Variable	Assignment
Education	Bachelor; education 1 (Master = 1, otherwise = 0); education 2 (Doctor = 1, otherwise = 0)
Age (years)	Continuous variables were considered as the model based on every year as a portion
Gender	Male = 1, female = 2
Nationality	Han = 1, others = 2
Marital status	Married = 1, others = 2
Number of kids (n)	0 = 1; ≥ 1 = 2
Job title	Physician; job title 1 (attending physician = 1, others = 0); job title 2 (deputy chief physician and advanced = 1, others = 0)
Position	Operating room anesthesia = 1, others = 2
Type of hospital	Tertiary A hospitals = 1, others = 2
Number of working overtime (day)	< 2 = 1, ≥ 2 = 2
Number of anesthesiologists (n)	< 20 = 1, 21-40 = 2, ≥ 41 = 3
Daily amount of anesthesia operations on average (n)	≤ 100 = 1, 101-200 = 2, ≥ 200 = 3